Python 使用Threading创建多线程

三种方法创建多线程

• 创建 Thread 的实例，传给它一个函数。
• 创建 Thread 的实例，传给它一个可调用的类实例。
• 派生 Thread 的子类，并创建子类的实例。

1、创建 Thread 的实例，传给它一个函数

上代码

import threading
from time import sleep,ctime

loops = [4,2]

def loop(nloop,nsec):
    print('start loop',nloop,'at:',ctime())
    sleep(nsec)
    print('loop',nloop,'done at:',ctime())

def main():
    print('starting at:',ctime())
    threads = []

    nloops = list(range(len(loops)))
    for i in nloops:
        t = threading.Thread(target=loop,
            args=(i,loops[i]))
        threads.append(t)

    for i in nloops: #开始多线程
        threads[i].start()

    for i in nloops: #等待所有线程完成
        threads[i].join()

    print('all done at:',ctime())

if __name__ == '__main__':
    main()

运行结果为：

starting at: Mon Aug 20 09:46:14 2018
start loop 0 at: Mon Aug 20 09:46:14 2018
start loop 1 at: Mon Aug 20 09:46:14 2018
loop 1 done at: Mon Aug 20 09:46:16 2018
loop 0 done at: Mon Aug 20 09:46:18 2018
all done at: Mon Aug 20 09:46:18 2018

2、创建 Thread 的实例，传给它一个可调用的类实例

import threading
from time import sleep,ctime

loops = [4,2]

class ThreadFunc(object):
    def __init__(self,func,args,name=''):
        self.name = name
        self.func = func
        self.args = args
    def __call__(self):
        self.func(*self.args)

def loop(nloop,nsec):
    print('start loop',nloop,'at:',ctime())
    sleep(nsec)
    print('loop',nloop,'done at:',ctime())

def main():
    print('starting at:',ctime())
    threads = []
    nloops = list(range(len(loops)))

    for i in nloops:
        t = threading.Thread(
            target=ThreadFunc(loop,(i,loops[i]),
                loop.__name__))
        threads.append(t)

    for i in nloops: #开始多线程
        threads[i].start()

    for i in nloops: #等待所有线程完成
        threads[i].join()

    print('all done at:',ctime())

if __name__ == '__main__':
    main()

运行结果为：

starting at: Mon Aug 20 09:43:49 2018
start loop 0 at: Mon Aug 20 09:43:49 2018
start loop 1 at: Mon Aug 20 09:43:49 2018
loop 1 done at: Mon Aug 20 09:43:51 2018
loop 0 done at: Mon Aug 20 09:43:53 2018
all done at: Mon Aug 20 09:43:53 2018

3、派生 Thread 的子类，并创建子类的实例

import threading
from time import sleep,ctime

loops = (4,2)

class MyThread(threading.Thread):
    def __init__(self, func, args, name=''):
        threading.Thread.__init__(self)
        self.name = name
        self.func = func
        self.args = args

    def run(self):
        self.func(*self.args)

def loop(nloop,nsec):
    print('start loop',nloop,'at:',ctime())
    sleep(nsec)
    print('loop',nloop,'done at:',ctime())

def main():
    print('starting at:',ctime())
    threads = []
    nloops = list(range(len(loops)))

    for i in nloops:
        t = MyThread(loop,(i,loops[i]),loop.__name__)
        threads.append(t)

    for i in nloops: #开始多线程
        threads[i].start()

    for i in nloops: #等待所有线程完成
        threads[i].join()

    print('all done at:',ctime())

if __name__ == '__main__':
    main()

运行结果为：

starting at: Mon Aug 20 09:52:43 2018
start loop 0 at: Mon Aug 20 09:52:43 2018
start loop 1 at: Mon Aug 20 09:52:43 2018
loop 1 done at: Mon Aug 20 09:52:45 2018
loop 0 done at: Mon Aug 20 09:52:47 2018
all done at: Mon Aug 20 09:52:47 2018